Yes, the S20 reed layout is identical to the Marine Band, Crossover etc

BTW, my previous reply that you can mix and match my Stealth-Valves across various brands is not strictly correct. That's because the angle of the reeds from longest to shortest varies. That's where the sets of valves differ, so best to buy the set that applies to the brand of harp you have.

Compressed felt/Mylar backed self adhesive windsaver valve for chromatic and diatonic harmonicas. Peel and stick! So simple, no glue required. Stays put! Will not absorb moisture! Will not jam up, will not flutter or slap. They are silent! Eliminates problems with windsavers sticking in cold weather! Price is for 1 windsaver valve. Rivet hole can be added upon request. These are precision cut and must be trimmed to the proper length after assembly. Video coming soon! Free shipping! Guaranteed to surpass your expectations!

Rather expensive but worth a try.
Will also try new windsavers from Brendan when they launch.